/* * Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * */ // A Klass is the part of the klassOop that provides: // 1: language level class object (method dictionary etc.) // 2: provide vm dispatch behavior for the object // Both functions are combined into one C++ class. The toplevel class "Klass" // implements purpose 1 whereas all subclasses provide extra virtual functions // for purpose 2. // One reason for the oop/klass dichotomy in the implementation is // that we don't want a C++ vtbl pointer in every object. Thus, // normal oops don't have any virtual functions. Instead, they // forward all "virtual" functions to their klass, which does have // a vtbl and does the C++ dispatch depending on the object's // actual type. (See oop.inline.hpp for some of the forwarding code.) // ALL FUNCTIONS IMPLEMENTING THIS DISPATCH ARE PREFIXED WITH "oop_"! // Klass layout: // [header ] klassOop // [klass pointer ] klassOop // [C++ vtbl ptr ] (contained in Klass_vtbl) // [layout_helper ] // [super_check_offset ] for fast subtype checks // [secondary_super_cache] for fast subtype checks // [secondary_supers ] array of 2ndary supertypes // [primary_supers 0] // [primary_supers 1] // [primary_supers 2] // ... // [primary_supers 7] // [java_mirror ] // [super ] // [name ] // [first subklass] // [next_sibling ] link to chain additional subklasses // [modifier_flags] // [access_flags ] // [verify_count ] - not in product // [alloc_count ] // [last_biased_lock_bulk_revocation_time] (64 bits) // [prototype_header] // [biased_lock_revocation_count] // Forward declarations. class klassVtable; class KlassHandle; class OrderAccess; // Holder (or cage) for the C++ vtable of each kind of Klass. // We want to tightly constrain the location of the C++ vtable in the overall layout. class Klass_vtbl { protected: // The following virtual exists only to force creation of a C++ vtable, // so that this class truly is the location of the vtable of all Klasses. virtual void unused_initial_virtual() { } public: // The following virtual makes Klass_vtbl play a second role as a // factory protocol for subclasses of Klass ("sub-Klasses"). // Here's how it works.... // // This VM uses metaobjects as factories for their instances. // // In order to initialize the C++ vtable of a new instance, its // metaobject is forced to use the C++ placed new operator to // allocate the instance. In a typical C++-based system, each // sub-class would have its own factory routine which // directly uses the placed new operator on the desired class, // and then calls the appropriate chain of C++ constructors. // // However, this system uses shared code to performs the first // allocation and initialization steps for all sub-Klasses. // (See base_create_klass() and base_create_array_klass().) // This does not factor neatly into a hierarchy of C++ constructors. // Each caller of these shared "base_create" routines knows // exactly which sub-Klass it is creating, but the shared routine // does not, even though it must perform the actual allocation. // // Therefore, the caller of the shared "base_create" must wrap // the specific placed new call in a virtual function which // performs the actual allocation and vtable set-up. That // virtual function is here, Klass_vtbl::allocate_permanent. // // The arguments to Universe::allocate_permanent() are passed // straight through the placed new operator, which in turn // obtains them directly from this virtual call. // // This virtual is called on a temporary "example instance" of the // sub-Klass being instantiated, a C++ auto variable. The "real" // instance created by this virtual is on the VM heap, where it is // equipped with a klassOopDesc header. // // It is merely an accident of implementation that we use "example // instances", but that is why the virtual function which implements // each sub-Klass factory happens to be defined by the same sub-Klass // for which it creates instances. // // The vtbl_value() call (see below) is used to strip away the // accidental Klass-ness from an "example instance" and present it as // a factory. Think of each factory object as a mere container of the // C++ vtable for the desired sub-Klass. Since C++ does not allow // direct references to vtables, the factory must also be delegated // the task of allocating the instance, but the essential point is // that the factory knows how to initialize the C++ vtable with the // right pointer value. All other common initializations are handled // by the shared "base_create" subroutines. // virtual void* allocate_permanent(KlassHandle& klass, int size, TRAPS) const = 0; void post_new_init_klass(KlassHandle& klass, klassOop obj, int size) const; // Every subclass on which vtbl_value is called must include this macro. // Delay the installation of the klassKlass pointer until after the // the vtable for a new klass has been installed (after the call to new()). #define DEFINE_ALLOCATE_PERMANENT(thisKlass) \ void* allocate_permanent(KlassHandle& klass_klass, int size, TRAPS) const { \ void* result = new(klass_klass, size, THREAD) thisKlass(); \ if (HAS_PENDING_EXCEPTION) return NULL; \ klassOop new_klass = ((Klass*) result)->as_klassOop(); \ OrderAccess::storestore(); \ post_new_init_klass(klass_klass, new_klass, size); \ return result; \ } bool null_vtbl() { return *(intptr_t*)this == 0; } protected: void* operator new(size_t ignored, KlassHandle& klass, int size, TRAPS); }; class Klass : public Klass_vtbl { friend class VMStructs; protected: // note: put frequently-used fields together at start of klass structure // for better cache behavior (may not make much of a difference but sure won't hurt) enum { _primary_super_limit = 8 }; // The "layout helper" is a combined descriptor of object layout. // For klasses which are neither instance nor array, the value is zero. // // For instances, layout helper is a positive number, the instance size. // This size is already passed through align_object_size and scaled to bytes. // The low order bit is set if instances of this class cannot be // allocated using the fastpath. // // For arrays, layout helper is a negative number, containing four // distinct bytes, as follows: // MSB:[tag, hsz, ebt, log2(esz)]:LSB // where: // tag is 0x80 if the elements are oops, 0xC0 if non-oops // hsz is array header size in bytes (i.e., offset of first element) // ebt is the BasicType of the elements // esz is the element size in bytes // This packed word is arranged so as to be quickly unpacked by the // various fast paths that use the various subfields. // // The esz bits can be used directly by a SLL instruction, without masking. // // Note that the array-kind tag looks like 0x00 for instance klasses, // since their length in bytes is always less than 24Mb. // // Final note: This comes first, immediately after Klass_vtbl, // because it is frequently queried. jint _layout_helper; // The fields _super_check_offset, _secondary_super_cache, _secondary_supers // and _primary_supers all help make fast subtype checks. See big discussion // in doc/server_compiler/checktype.txt // // Where to look to observe a supertype (it is &_secondary_super_cache for // secondary supers, else is &_primary_supers[depth()]. juint _super_check_offset; public: oop* oop_block_beg() const { return adr_secondary_super_cache(); } oop* oop_block_end() const { return adr_next_sibling() + 1; } protected: // // The oop block. All oop fields must be declared here and only oop fields // may be declared here. In addition, the first and last fields in this block // must remain first and last, unless oop_block_beg() and/or oop_block_end() // are updated. Grouping the oop fields in a single block simplifies oop // iteration. // // Cache of last observed secondary supertype klassOop _secondary_super_cache; // Array of all secondary supertypes objArrayOop _secondary_supers; // Ordered list of all primary supertypes klassOop _primary_supers[_primary_super_limit]; // java/lang/Class instance mirroring this class oop _java_mirror; // Superclass klassOop _super; // Class name. Instance classes: java/lang/String, etc. Array classes: [I, // [Ljava/lang/String;, etc. Set to zero for all other kinds of classes. symbolOop _name; // First subclass (NULL if none); _subklass->next_sibling() is next one klassOop _subklass; // Sibling link (or NULL); links all subklasses of a klass klassOop _next_sibling; // // End of the oop block. // jint _modifier_flags; // Processed access flags, for use by Class.getModifiers. AccessFlags _access_flags; // Access flags. The class/interface distinction is stored here. #ifndef PRODUCT int _verify_count; // to avoid redundant verifies #endif juint _alloc_count; // allocation profiling support - update klass_size_in_bytes() if moved/deleted // Biased locking implementation and statistics // (the 64-bit chunk goes first, to avoid some fragmentation) jlong _last_biased_lock_bulk_revocation_time; markOop _prototype_header; // Used when biased locking is both enabled and disabled for this type jint _biased_lock_revocation_count; public: // returns the enclosing klassOop klassOop as_klassOop() const { // see klassOop.hpp for layout. return (klassOop) (((char*) this) - sizeof(klassOopDesc)); } public: // Allocation const Klass_vtbl& vtbl_value() const { return *this; } // used only on "example instances" static KlassHandle base_create_klass(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS); static klassOop base_create_klass_oop(KlassHandle& klass, int size, const Klass_vtbl& vtbl, TRAPS); // super klassOop super() const { return _super; } void set_super(klassOop k) { oop_store_without_check((oop*) &_super, (oop) k); } // initializes _super link, _primary_supers & _secondary_supers arrays void initialize_supers(klassOop k, TRAPS); void initialize_supers_impl1(klassOop k); void initialize_supers_impl2(klassOop k); // klass-specific helper for initializing _secondary_supers virtual objArrayOop compute_secondary_supers(int num_extra_slots, TRAPS); // java_super is the Java-level super type as specified by Class.getSuperClass. virtual klassOop java_super() const { return NULL; } juint super_check_offset() const { return _super_check_offset; } void set_super_check_offset(juint o) { _super_check_offset = o; } klassOop secondary_super_cache() const { return _secondary_super_cache; } void set_secondary_super_cache(klassOop k) { oop_store_without_check((oop*) &_secondary_super_cache, (oop) k); } objArrayOop secondary_supers() const { return _secondary_supers; } void set_secondary_supers(objArrayOop k) { oop_store_without_check((oop*) &_secondary_supers, (oop) k); } // Return the element of the _super chain of the given depth. // If there is no such element, return either NULL or this. klassOop primary_super_of_depth(juint i) const { assert(i < primary_super_limit(), "oob"); klassOop super = _primary_supers[i]; assert(super == NULL || super->klass_part()->super_depth() == i, "correct display"); return super; } // Can this klass be a primary super? False for interfaces and arrays of // interfaces. False also for arrays or classes with long super chains. bool can_be_primary_super() const { const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc); return super_check_offset() != secondary_offset; } virtual bool can_be_primary_super_slow() const; // Returns number of primary supers; may be a number in the inclusive range [0, primary_super_limit]. juint super_depth() const { if (!can_be_primary_super()) { return primary_super_limit(); } else { juint d = (super_check_offset() - (primary_supers_offset_in_bytes() + sizeof(oopDesc))) / sizeof(klassOop); assert(d < primary_super_limit(), "oob"); assert(_primary_supers[d] == as_klassOop(), "proper init"); return d; } } // java mirror oop java_mirror() const { return _java_mirror; } void set_java_mirror(oop m) { oop_store((oop*) &_java_mirror, m); } // modifier flags jint modifier_flags() const { return _modifier_flags; } void set_modifier_flags(jint flags) { _modifier_flags = flags; } // size helper int layout_helper() const { return _layout_helper; } void set_layout_helper(int lh) { _layout_helper = lh; } // Note: for instances layout_helper() may include padding. // Use instanceKlass::contains_field_offset to classify field offsets. // sub/superklass links instanceKlass* superklass() const; Klass* subklass() const; Klass* next_sibling() const; void append_to_sibling_list(); // add newly created receiver to superklass' subklass list void remove_from_sibling_list(); // remove receiver from sibling list protected: // internal accessors klassOop subklass_oop() const { return _subklass; } klassOop next_sibling_oop() const { return _next_sibling; } void set_subklass(klassOop s); void set_next_sibling(klassOop s); oop* adr_super() const { return (oop*)&_super; } oop* adr_primary_supers() const { return (oop*)&_primary_supers[0]; } oop* adr_secondary_super_cache() const { return (oop*)&_secondary_super_cache; } oop* adr_secondary_supers()const { return (oop*)&_secondary_supers; } oop* adr_java_mirror() const { return (oop*)&_java_mirror; } oop* adr_name() const { return (oop*)&_name; } oop* adr_subklass() const { return (oop*)&_subklass; } oop* adr_next_sibling() const { return (oop*)&_next_sibling; } public: // Allocation profiling support juint alloc_count() const { return _alloc_count; } void set_alloc_count(juint n) { _alloc_count = n; } virtual juint alloc_size() const = 0; virtual void set_alloc_size(juint n) = 0; // Compiler support static int super_offset_in_bytes() { return offset_of(Klass, _super); } static int super_check_offset_offset_in_bytes() { return offset_of(Klass, _super_check_offset); } static int primary_supers_offset_in_bytes(){ return offset_of(Klass, _primary_supers); } static int secondary_super_cache_offset_in_bytes() { return offset_of(Klass, _secondary_super_cache); } static int secondary_supers_offset_in_bytes() { return offset_of(Klass, _secondary_supers); } static int java_mirror_offset_in_bytes() { return offset_of(Klass, _java_mirror); } static int modifier_flags_offset_in_bytes(){ return offset_of(Klass, _modifier_flags); } static int layout_helper_offset_in_bytes() { return offset_of(Klass, _layout_helper); } static int access_flags_offset_in_bytes() { return offset_of(Klass, _access_flags); } // Unpacking layout_helper: enum { _lh_neutral_value = 0, // neutral non-array non-instance value _lh_instance_slow_path_bit = 0x01, _lh_log2_element_size_shift = BitsPerByte*0, _lh_log2_element_size_mask = BitsPerLong-1, _lh_element_type_shift = BitsPerByte*1, _lh_element_type_mask = right_n_bits(BitsPerByte), // shifted mask _lh_header_size_shift = BitsPerByte*2, _lh_header_size_mask = right_n_bits(BitsPerByte), // shifted mask _lh_array_tag_bits = 2, _lh_array_tag_shift = BitsPerInt - _lh_array_tag_bits, _lh_array_tag_type_value = ~0x00, // 0xC0000000 >> 30 _lh_array_tag_obj_value = ~0x01 // 0x80000000 >> 30 }; static int layout_helper_size_in_bytes(jint lh) { assert(lh > (jint)_lh_neutral_value, "must be instance"); return (int) lh & ~_lh_instance_slow_path_bit; } static bool layout_helper_needs_slow_path(jint lh) { assert(lh > (jint)_lh_neutral_value, "must be instance"); return (lh & _lh_instance_slow_path_bit) != 0; } static bool layout_helper_is_instance(jint lh) { return (jint)lh > (jint)_lh_neutral_value; } static bool layout_helper_is_javaArray(jint lh) { return (jint)lh < (jint)_lh_neutral_value; } static bool layout_helper_is_typeArray(jint lh) { // _lh_array_tag_type_value == (lh >> _lh_array_tag_shift); return (juint)lh >= (juint)(_lh_array_tag_type_value << _lh_array_tag_shift); } static bool layout_helper_is_objArray(jint lh) { // _lh_array_tag_obj_value == (lh >> _lh_array_tag_shift); return (jint)lh < (jint)(_lh_array_tag_type_value << _lh_array_tag_shift); } static int layout_helper_header_size(jint lh) { assert(lh < (jint)_lh_neutral_value, "must be array"); int hsize = (lh >> _lh_header_size_shift) & _lh_header_size_mask; assert(hsize > 0 && hsize < (int)sizeof(oopDesc)*3, "sanity"); return hsize; } static BasicType layout_helper_element_type(jint lh) { assert(lh < (jint)_lh_neutral_value, "must be array"); int btvalue = (lh >> _lh_element_type_shift) & _lh_element_type_mask; assert(btvalue >= T_BOOLEAN && btvalue <= T_OBJECT, "sanity"); return (BasicType) btvalue; } static int layout_helper_log2_element_size(jint lh) { assert(lh < (jint)_lh_neutral_value, "must be array"); int l2esz = (lh >> _lh_log2_element_size_shift) & _lh_log2_element_size_mask; assert(l2esz <= LogBitsPerLong, "sanity"); return l2esz; } static jint array_layout_helper(jint tag, int hsize, BasicType etype, int log2_esize) { return (tag << _lh_array_tag_shift) | (hsize << _lh_header_size_shift) | ((int)etype << _lh_element_type_shift) | (log2_esize << _lh_log2_element_size_shift); } static jint instance_layout_helper(jint size, bool slow_path_flag) { return (size << LogHeapWordSize) | (slow_path_flag ? _lh_instance_slow_path_bit : 0); } static int layout_helper_to_size_helper(jint lh) { assert(lh > (jint)_lh_neutral_value, "must be instance"); // Note that the following expression discards _lh_instance_slow_path_bit. return lh >> LogHeapWordSize; } // Out-of-line version computes everything based on the etype: static jint array_layout_helper(BasicType etype); // What is the maximum number of primary superclasses any klass can have? #ifdef PRODUCT static juint primary_super_limit() { return _primary_super_limit; } #else static juint primary_super_limit() { assert(FastSuperclassLimit <= _primary_super_limit, "parameter oob"); return FastSuperclassLimit; } #endif // vtables virtual klassVtable* vtable() const { return NULL; } static int klass_size_in_bytes() { return offset_of(Klass, _alloc_count) + sizeof(juint); } // all "visible" fields // subclass check bool is_subclass_of(klassOop k) const; // subtype check: true if is_subclass_of, or if k is interface and receiver implements it bool is_subtype_of(klassOop k) const { juint off = k->klass_part()->super_check_offset(); klassOop sup = *(klassOop*)( (address)as_klassOop() + off ); const juint secondary_offset = secondary_super_cache_offset_in_bytes() + sizeof(oopDesc); if (sup == k) { return true; } else if (off != secondary_offset) { return false; } else { return search_secondary_supers(k); } } bool search_secondary_supers(klassOop k) const; // Find LCA in class heirarchy Klass *LCA( Klass *k ); // Check whether reflection/jni/jvm code is allowed to instantiate this class; // if not, throw either an Error or an Exception. virtual void check_valid_for_instantiation(bool throwError, TRAPS); // Casting static Klass* cast(klassOop k) { assert(k->is_klass(), "cast to Klass"); return k->klass_part(); } // array copying virtual void copy_array(arrayOop s, int src_pos, arrayOop d, int dst_pos, int length, TRAPS); // tells if the class should be initialized virtual bool should_be_initialized() const { return false; } // initializes the klass virtual void initialize(TRAPS); // lookup operation for MethodLookupCache friend class MethodLookupCache; virtual methodOop uncached_lookup_method(symbolOop name, symbolOop signature) const; public: methodOop lookup_method(symbolOop name, symbolOop signature) const { return uncached_lookup_method(name, signature); } // array class with specific rank klassOop array_klass(int rank, TRAPS) { return array_klass_impl(false, rank, THREAD); } // array class with this klass as element type klassOop array_klass(TRAPS) { return array_klass_impl(false, THREAD); } // These will return NULL instead of allocating on the heap: // NB: these can block for a mutex, like other functions with TRAPS arg. klassOop array_klass_or_null(int rank); klassOop array_klass_or_null(); virtual oop protection_domain() { return NULL; } virtual oop class_loader() const { return NULL; } protected: virtual klassOop array_klass_impl(bool or_null, int rank, TRAPS); virtual klassOop array_klass_impl(bool or_null, TRAPS); public: virtual void remove_unshareable_info(); protected: // computes the subtype relationship virtual bool compute_is_subtype_of(klassOop k); public: // subclass accessor (here for convenience; undefined for non-klass objects) virtual bool is_leaf_class() const { fatal("not a class"); return false; } public: // ALL FUNCTIONS BELOW THIS POINT ARE DISPATCHED FROM AN OOP // These functions describe behavior for the oop not the KLASS. // actual oop size of obj in memory virtual int oop_size(oop obj) const = 0; // actual oop size of this klass in memory virtual int klass_oop_size() const = 0; // Returns the Java name for a class (Resource allocated) // For arrays, this returns the name of the element with a leading '['. // For classes, this returns the name with the package separators // turned into '.'s. const char* external_name() const; // Returns the name for a class (Resource allocated) as the class // would appear in a signature. // For arrays, this returns the name of the element with a leading '['. // For classes, this returns the name with a leading 'L' and a trailing ';' // and the package separators as '/'. virtual char* signature_name() const; // garbage collection support virtual void oop_follow_contents(oop obj) = 0; virtual int oop_adjust_pointers(oop obj) = 0; // Parallel Scavenge and Parallel Old PARALLEL_GC_DECLS_PV public: // type testing operations virtual bool oop_is_instance_slow() const { return false; } virtual bool oop_is_instanceRef() const { return false; } virtual bool oop_is_array() const { return false; } virtual bool oop_is_objArray_slow() const { return false; } virtual bool oop_is_symbol() const { return false; } virtual bool oop_is_klass() const { return false; } virtual bool oop_is_thread() const { return false; } virtual bool oop_is_method() const { return false; } virtual bool oop_is_constMethod() const { return false; } virtual bool oop_is_methodData() const { return false; } virtual bool oop_is_constantPool() const { return false; } virtual bool oop_is_constantPoolCache() const { return false; } virtual bool oop_is_typeArray_slow() const { return false; } virtual bool oop_is_arrayKlass() const { return false; } virtual bool oop_is_objArrayKlass() const { return false; } virtual bool oop_is_typeArrayKlass() const { return false; } virtual bool oop_is_compiledICHolder() const { return false; } virtual bool oop_is_instanceKlass() const { return false; } bool oop_is_javaArray_slow() const { return oop_is_objArray_slow() || oop_is_typeArray_slow(); } // Fast non-virtual versions, used by oop.inline.hpp and elsewhere: #ifndef ASSERT #define assert_same_query(xval, xcheck) xval #else private: static bool assert_same_query(bool xval, bool xslow) { assert(xval == xslow, "slow and fast queries agree"); return xval; } public: #endif inline bool oop_is_instance() const { return assert_same_query( layout_helper_is_instance(layout_helper()), oop_is_instance_slow()); } inline bool oop_is_javaArray() const { return assert_same_query( layout_helper_is_javaArray(layout_helper()), oop_is_javaArray_slow()); } inline bool oop_is_objArray() const { return assert_same_query( layout_helper_is_objArray(layout_helper()), oop_is_objArray_slow()); } inline bool oop_is_typeArray() const { return assert_same_query( layout_helper_is_typeArray(layout_helper()), oop_is_typeArray_slow()); } #undef assert_same_query // Unless overridden, oop is parsable if it has a klass pointer. // Parsability of an object is object specific. virtual bool oop_is_parsable(oop obj) const { return true; } // Unless overridden, oop is safe for concurrent GC processing // after its allocation is complete. The exception to // this is the case where objects are changed after allocation. // Class redefinition is one of the known exceptions. During // class redefinition, an allocated class can changed in order // order to create a merged class (the combiniation of the // old class definition that has to be perserved and the new class // definition which is being created. virtual bool oop_is_conc_safe(oop obj) const { return true; } // Access flags AccessFlags access_flags() const { return _access_flags; } void set_access_flags(AccessFlags flags) { _access_flags = flags; } bool is_public() const { return _access_flags.is_public(); } bool is_final() const { return _access_flags.is_final(); } bool is_interface() const { return _access_flags.is_interface(); } bool is_abstract() const { return _access_flags.is_abstract(); } bool is_super() const { return _access_flags.is_super(); } bool is_synthetic() const { return _access_flags.is_synthetic(); } void set_is_synthetic() { _access_flags.set_is_synthetic(); } bool has_finalizer() const { return _access_flags.has_finalizer(); } bool has_final_method() const { return _access_flags.has_final_method(); } void set_has_finalizer() { _access_flags.set_has_finalizer(); } void set_has_final_method() { _access_flags.set_has_final_method(); } bool is_cloneable() const { return _access_flags.is_cloneable(); } void set_is_cloneable() { _access_flags.set_is_cloneable(); } bool has_vanilla_constructor() const { return _access_flags.has_vanilla_constructor(); } void set_has_vanilla_constructor() { _access_flags.set_has_vanilla_constructor(); } bool has_miranda_methods () const { return access_flags().has_miranda_methods(); } void set_has_miranda_methods() { _access_flags.set_has_miranda_methods(); } // Biased locking support // Note: the prototype header is always set up to be at least the // prototype markOop. If biased locking is enabled it may further be // biasable and have an epoch. markOop prototype_header() const { return _prototype_header; } // NOTE: once instances of this klass are floating around in the // system, this header must only be updated at a safepoint. // NOTE 2: currently we only ever set the prototype header to the // biasable prototype for instanceKlasses. There is no technical // reason why it could not be done for arrayKlasses aside from // wanting to reduce the initial scope of this optimization. There // are potential problems in setting the bias pattern for // JVM-internal oops. inline void set_prototype_header(markOop header); static int prototype_header_offset_in_bytes() { return offset_of(Klass, _prototype_header); } int biased_lock_revocation_count() const { return (int) _biased_lock_revocation_count; } // Atomically increments biased_lock_revocation_count and returns updated value int atomic_incr_biased_lock_revocation_count(); void set_biased_lock_revocation_count(int val) { _biased_lock_revocation_count = (jint) val; } jlong last_biased_lock_bulk_revocation_time() { return _last_biased_lock_bulk_revocation_time; } void set_last_biased_lock_bulk_revocation_time(jlong cur_time) { _last_biased_lock_bulk_revocation_time = cur_time; } // garbage collection support virtual void follow_weak_klass_links( BoolObjectClosure* is_alive, OopClosure* keep_alive); // Prefetch within oop iterators. This is a macro because we // can't guarantee that the compiler will inline it. In 64-bit // it generally doesn't. Signature is // // static void prefetch_beyond(oop* const start, // oop* const end, // const intx foffset, // const Prefetch::style pstyle); #define prefetch_beyond(start, end, foffset, pstyle) { \ const intx foffset_ = (foffset); \ const Prefetch::style pstyle_ = (pstyle); \ assert(foffset_ > 0, "prefetch beyond, not behind"); \ if (pstyle_ != Prefetch::do_none) { \ oop* ref = (start); \ if (ref < (end)) { \ switch (pstyle_) { \ case Prefetch::do_read: \ Prefetch::read(*ref, foffset_); \ break; \ case Prefetch::do_write: \ Prefetch::write(*ref, foffset_); \ break; \ default: \ ShouldNotReachHere(); \ break; \ } \ } \ } \ } // iterators virtual int oop_oop_iterate(oop obj, OopClosure* blk) = 0; virtual int oop_oop_iterate_v(oop obj, OopClosure* blk) { return oop_oop_iterate(obj, blk); } #ifndef SERIALGC // In case we don't have a specialized backward scanner use forward // iteration. virtual int oop_oop_iterate_backwards_v(oop obj, OopClosure* blk) { return oop_oop_iterate_v(obj, blk); } #endif // !SERIALGC // Iterates "blk" over all the oops in "obj" (of type "this") within "mr". // (I don't see why the _m should be required, but without it the Solaris // C++ gives warning messages about overridings of the "oop_oop_iterate" // defined above "hiding" this virtual function. (DLD, 6/20/00)) */ virtual int oop_oop_iterate_m(oop obj, OopClosure* blk, MemRegion mr) = 0; virtual int oop_oop_iterate_v_m(oop obj, OopClosure* blk, MemRegion mr) { return oop_oop_iterate_m(obj, blk, mr); } // Versions of the above iterators specialized to particular subtypes // of OopClosure, to avoid closure virtual calls. #define Klass_OOP_OOP_ITERATE_DECL(OopClosureType, nv_suffix) \ virtual int oop_oop_iterate##nv_suffix(oop obj, OopClosureType* blk) { \ /* Default implementation reverts to general version. */ \ return oop_oop_iterate(obj, blk); \ } \ \ /* Iterates "blk" over all the oops in "obj" (of type "this") within "mr". \ (I don't see why the _m should be required, but without it the Solaris \ C++ gives warning messages about overridings of the "oop_oop_iterate" \ defined above "hiding" this virtual function. (DLD, 6/20/00)) */ \ virtual int oop_oop_iterate##nv_suffix##_m(oop obj, \ OopClosureType* blk, \ MemRegion mr) { \ return oop_oop_iterate_m(obj, blk, mr); \ } SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_DECL) SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_DECL) #ifndef SERIALGC #define Klass_OOP_OOP_ITERATE_BACKWARDS_DECL(OopClosureType, nv_suffix) \ virtual int oop_oop_iterate_backwards##nv_suffix(oop obj, \ OopClosureType* blk) { \ /* Default implementation reverts to general version. */ \ return oop_oop_iterate_backwards_v(obj, blk); \ } SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_1(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) SPECIALIZED_OOP_OOP_ITERATE_CLOSURES_2(Klass_OOP_OOP_ITERATE_BACKWARDS_DECL) #endif // !SERIALGC virtual void array_klasses_do(void f(klassOop k)) {} virtual void with_array_klasses_do(void f(klassOop k)); // Return self, except for abstract classes with exactly 1 // implementor. Then return the 1 concrete implementation. Klass *up_cast_abstract(); // klass name symbolOop name() const { return _name; } void set_name(symbolOop n) { oop_store_without_check((oop*) &_name, (oop) n); } friend class klassKlass; public: // jvm support virtual jint compute_modifier_flags(TRAPS) const; public: // JVMTI support virtual jint jvmti_class_status() const; #ifndef PRODUCT public: // Printing virtual void oop_print_on (oop obj, outputStream* st); virtual void oop_print_value_on(oop obj, outputStream* st); #endif public: // Verification virtual const char* internal_name() const = 0; virtual void oop_verify_on(oop obj, outputStream* st); virtual void oop_verify_old_oop(oop obj, oop* p, bool allow_dirty); virtual void oop_verify_old_oop(oop obj, narrowOop* p, bool allow_dirty); // tells whether obj is partially constructed (gc during class loading) virtual bool oop_partially_loaded(oop obj) const { return false; } virtual void oop_set_partially_loaded(oop obj) {}; #ifndef PRODUCT void verify_vtable_index(int index); #endif };